Several law enforcement agencies are on puffer patrol, looking for vehicles that are being warmed up but are unattended.

Such vehicles account for a large amount of motor vehicle thefts across the state.

"It's common sense," Aurora police officer Bill Hummel said. "It's something that makes it easier to get your car stolen. We want people to make it hard to get their car stolen. We don't want people to become victims."

A kill switch or a remote start is fine as long as the keys aren't inside the unattended vehicle.